The corn crop is very technological and this productive system absorbs all possible innovations to improve the yield, nevertheless some care should be taken concerning the addition of new chemicals to the seeds. The objective of this study was to evaluate the effect of seed treatment, with the biostimulant Stimulate® as well with the liquid fertilizer Cellerate® at 6 months before sowing and in the pre- sowing, on the physiological quality of seeds, on corn yield. Experiments were performed at the Federal University of Lavras, MG, Brazil in 2005, at field and laboratory level with a corn hybrid (GNZ 2004) and with a corn line (L57). The treatments used for corn assays were: witness (without chemicals); 5 mL.kg-1 Stimulate®; 5 and 10 mL.kg-1 Cellerate®. The seed physiological quality was accessed by germination, EVI, cold test and above and under ground dry mass of plantlets and by the analysis of the enzymes esterase, superoxide dismutase, malate dehydrogenase, alcohol dehydrogenase, catalase and á-amylase. The laboratory experiments were carried out in a complete randomized design with four replications. The a randomized block design was used of hybrid and line corn field with four replicates in a 4 x 2 factorial with the time and the compounds for seed treatment being the factors. In this assay plant and spike height, number of spikes per plant and productivity were evaluated. Corn seeds treated with Stimulate® and Cellerate® promoted greater plantlet development in the line and of roots in the hybrid. A high concentration of Cellerate® seems to reduce hybrid emergence and germination as well as the emergence of the line seeds when they have been treated at the pre-sowing stage. An increase was observed in the activity of the enzymes malato dehydrogenase and catalase in the hybrid seeds treated with the high concentration of Cellerate® in the pre-sowing and 6 months before sowing, respectively. However, the line seeds when treated with high concentrations of Cellerate® in the pre-sowing stage showed a reduction in malate dehydrogenase activity and increase in alcohol dehydrogenase activity. The activity of á-amylase was higher in the hybrid seeds treated with Stimulate® before the storage and with dosage 1 of Cellerate® in the pre-sowing and the lineage seeds presented greater á-amylase activity when treated with Stimulate® at pre-sowing. The corn yield was not affected by the treatments.
Zea mays; growth regulator; zinc; molibdenium
